Recording apparatus and electronic apparatus

ABSTRACT

A recording apparatus provided with an interface for supplying an electric power to a connected electronic apparatus, and capable of performing a recording operation on a recording medium by the use of a recording head. A power source supplying unit supplies predetermined electric power to the electronic apparatus connected to the interface, and a detecting unit detects that the electronic apparatus has been connected. An acquiring unit acquires power information of the electronic apparatus, such as information indicating the nature of the interface or information indicating the power requirements. Based on detection of the connection by the detecting unit and the power information acquired by the acquiring unit, a control unit effects a change over of control of the recording operation.

This application is a divisional of application Ser. No. 10/859,338,filed Jun. 3, 2004, now allowed, the contents of which are incorporatedby reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an electronic apparatus, and particularly toan apparatus for effecting electric power supply to an apparatusconnected thereto.

2. Related Background Art

With the spread of personal computers, digital cameras, etc., the higherdefinition of recording apparatuses such as printers for recording imagedata of a digital type has been advanced. Among the recordingapparatuses, an ink jet recording apparatus using a recording head of anink jet type has rapidly spread, and there is demand for one whichrealizes images of high definition and is low in price.

In an ink jet recording apparatus of a serial scan type, Recording iseffected while a recording head is scanned in a direction (main scanningdirection orthogonal to the conveying direction of a recording mediumsuch as recording paper, and at a stage whereat one scan of recordinghas been finished, the recording medium is conveyed, and by therepetition thereof, an image is formed.

In recent years, user's demand for printing in a recording apparatusdirectly from a digital camera without the intermediary of a hostcomputer has become high, and the direct printing function of effectingprint directly from an apparatus provided with an image pickup elementsuch as a digital camera onto a recording apparatus has become afunction necessary for the recording apparatus.

Heretofore, in a recording apparatus supporting the direct printingfunction, USB has been used as an interface. One of the features of USBis that it can supply a power source from a host side to a peripheraldevice (USB device) through a USB cable. The supplied electric currentis 500 mA at maximum per peripheral device. There has been adopted aconstruction in which the recording apparatus is provided with thefunction of a USB host and, it is connected to a digital camera as a USBdevice (function), but connectable digital cameras have been restricted.These connectable digital cameras have been of the so-called self powertype operable even without a power source being supplied from the USBhost.

Therefore, as the recording apparatus, it has been enough if it has thecapability of supplying an electric current of 100 mA or less to Vbuswhich is the power supply line of USB. Also, if the connected USB devicehas pulled up 100 mA or greater from the Vbus, it has been detected that100 mA or greater has been pulled up, and the Vbus has been forciblydisconnected. The electric current supplied by the Vbus is small, andtherefore, a load to the power source of the recording apparatus islight. Accordingly, in a case where a digital camera is connected to theUSB host and in a case where a digital camera is not connected to theUSB host, there has not occurred the necessity of changing a printingmode (recording mode) or the like for the reason of the load of thepower source.

Also, in order to reduce the cost of a power supply device (power supplycircuit), there has been the technique of effecting the control of arecording operation in conformity with recording data. For example, arecording duty (the value of a recording duty) is detected and iscompared with a preset duty value to thereby change the recordingoperation. Thereby, the balance between the throughput of recording andthe cost for the power supply is kept.

In recent years, however, cases where a bus power device activated bybeing supplied with a power source from the USB host is connected areincreasing due to the diversification of USB device to be connected.Therefore, the power source capacity which must be supplied from theVbus of a USB interface has increased. Specifically, maximum 500 mA mustbe capable of being supplied. In order to solve this problem, thecapability of the power source of the recording apparatus can beincreased, but this will result in a power source of high cost. In otherwords, how 500 mA can be supplied to the Vbus while the cost of therecording apparatus is suppressed is a task.

SUMMARY OF THE INVENTION

In order to solve the above task and achieve an object, the recordingapparatus of the present invention is a recording apparatus forreceiving recording data from an electronic apparatus or a host computeractivated by being supplied with a power source through an interface,and performing a recording operation on a recording medium by the use ofa recording head, comprising:

power source supplying means for supplying predetermined electric powerto the electronic apparatus, detecting means for detecting that theelectronic apparatus has been connected, and control means for changingover the control of the recording operation when the detecting means hasdetected the connection or non-connection of the electronic apparatus.

Also, in order to achieve the object, the electronic apparatus of thepresent invention is an electronic apparatus for effecting communicationwith a first external device activated by being supplied with a powersource through a first interface and a second external device connectedthereto through a second interface, and performing an operation,comprising:

power source supplying means for supplying predetermined electric powerto the first external device;

detecting means for detecting that the first external device has beenconnected; and

control means for changing over the control of the operation when thedetecting means has detected the connection or non-connection of thefirst external device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram schematically showing the construction of arecording apparatus in first, second and third embodiments.

FIG. 2 is an illustration of power source supplying means in the first,second and third embodiments.

FIGS. 3A, 3B and 3C are illustrations of the detection unit of arecording duty.

FIGS. 4A, 4B and 4C are illustrations of the comparison of the recordingduty.

FIG. 5 is a flow chart of the first embodiment.

FIG. 6 is a flow chart of the second embodiment.

FIG. 7 is a flow chart of the second embodiment.

FIGS. 8A, 8B and 8C show electric currents consumed by a carriage motorand a conveying motor in a third embodiment.

FIGS. 9A, 9B and 9C show electric currents consumed by a carriage motorand a conveying motor according to the prior art.

FIG. 10 is a flow chart of the third embodiment.

FIG. 11 is a block diagram regarding a recording apparatus according toa fifth embodiment.

FIG. 12 is an illustration of power source supplying means in the fifthembodiment.

FIG. 13 is a flow chart of the fifth embodiment.

FIG. 14 is a perspective view of the recording apparatus in the firstembodiment to the fifth embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will hereinafter be described in detail withreference to the drawings.

First Embodiment

FIG. 1 is a block diagram schematically showing an example of theconstruction of a recording apparatus according to a first embodiment.In FIG. 1, the reference numeral 100 designates a control board on whichelectric parts for effecting the control of the recording apparatus aremounted.

The reference numeral 101 denotes a system LSI. This system LSI includesa CPU_CORE (or CPU) 102, an interface control circuit 103, a datacontrol circuit 104, a print data generating circuit 105, a recordinghead control circuit 106 and a motor control circuit 107.

The interface control circuit 103 effects the transmission and receptionof data with a host computer 118 and a digital camera 119 through aninterface 110. This data is stored in a reception buffer provided in aRAM 109.

The data control circuit 104 effects the read/write control of the datato the reception buffer and a print buffer. The print data generatingcircuit 105 generates print data from the received data.

The recording head control circuit 106 forwards the generated print datato a recording head 115 and effects the discharge control of the ink ofthe recording head.

The motor control circuit 107 outputs a control signal to a motor driver113 for driving motors 114. The motors include a carriage motor forcausing a carriage carrying the recording head 115 thereon to scan, aconveying motor for effecting the conveyance of a recording medium, afeeding/discharge motor for effecting the feeding and discharge of therecording medium, and a maintenance motor for effecting the cleaning(maintenance) of the recording head.

The reference numeral 108 designates a ROM storing therein a program forcontrolling the printer.

The printing operation of the recording apparatus will now be described.When the recording apparatus receives image data or the like from thehost computer 118 through the interface 110, the received data is oncestored in the reception buffer allotted to the RAM 109 from theinterface control circuit 103 of the system LSI 101 by the data controlcircuit 104.

The received data stored in the reception buffer is subjected to commandanalysis, and the image data is subjected to print data processing bythe print data generating circuit 105, and then is stored in the printbuffer allotted to the RAM 109.

When a necessary amount of data is stored in the print buffer, printdata is read out from the print buffer at predetermined timing by therecording head control circuit 106, and is forwarded to the recordinghead 115.

Further, a driving pulse (driving signal) is outputted to the recordinghead 115 by the recording head control circuit 106 while the recordinghead is moved in a main scanning direction. Thereby, the printingoperation is performed and an image is formed on the recording medium(e.g. recording paper).

The recording operation of the recording head 115 is performed by thecarriage motor, the conveying motor and the feeding/discharge motorbeing driven by the motor control circuit 107 through a motor driver113.

Again in a case where data from the digital camera 119 has beenreceived, image processing such as a binarizing process is effected,whereafter the generation of the print data is effected and processingsimilar to the above-described processing is effected, whereby therecording (printing) operation is performed.

Power source supplying means (power source supplying circuit) will nowbe described with reference to FIG. 2. The reference numeral 201 denotesthe power supply of the recording apparatus. In the present embodiments,the power supply outputs of two systems, i.e., VM which is a powersupply for driving the motors, and VH used for the ink discharge of therecording head, are effected.

A producing means of power supply for logics 202 for supplying power tothe system LSI, the ROM and the RAM is equipped with a step-down type ofDC/DC converter, and the converter converts the voltage from the VM tooutput thus converted voltages.

In the present embodiment, there are produced the power supplies ofthree systems, i.e., 1.5 volts for operating the logic circuit of thesystem LSI, and 3.3 volts and 5 volts used as the input/output of theROM, RAM and the system LSI.

The connection of the recording apparatus to the digital camera, in thepresent embodiment, is done by a USB interface. A signal line comprisesthe Vbus of power supply, D+ and D− of data lines, and GND (ground).

In the present embodiment, means for detecting the connection of anapparatus (e.g. a digital camera) provided with an image pickup elementconforms to the standard of USB. Specifically, a USB device has apull-up resistor at either of the data lines, and the connection can bedetected by the device being connected to the port of a hub or a hostand one of the data lines being pulled up to a threshold at a high sideor greater for a period of 2.5 μs (microseconds) or longer.

Any USB device, when first connected, does not require electric powergreater than 100 mA. The host (USB host) usually requires configurationinformation of the USB device, examines the function of a device to beconnected and effects the making of the device.

At that time, the host, when it detects the mounting of a USB deviceusing a bus power supply, effects the estimate of the consumed electricpower of the device.

The present embodiment is designed such that in a case where a digitalcamera activated by being supplied with electric power through aninterface is connected, when the connection (connected state) isdetected by the USB host circuit of the recording apparatus, therecording operation is performed with the consumed electric power(electric power load) of the recording apparatus suppressed. Or it isdesigned such that when the detachment (non-connected state) of a USBcable is detected, the suppression of the consumed electric power of therecording apparatus is stopped and the state before the connection isrestored.

That is, design is made such that whether the digital camera and therecording apparatus are connected together is detected and control ischanged depending on the result of the detection.

Description will now be made of an example of the control of suppressingthe consumed electric power of the recording operation. This control iseffected so as to perform the recording operation in accordance with theamount of recording data (recording duty) received from the hostapparatus. When the amount of recording data is great, the control ofdecreasing the number of nozzles used in one cycle of scanning isexecuted. Thereby, the electric power consumed by the recording head issuppressed.

First, in the recording medium, the area of a print buffer correspondingto a recording area capable of recording by one scan of the recordinghead is divided into a plurality to thereby form a plurality of blocks,and a record duty (represented also as a record duty value or the valueof recording density) in each block is calculated (detected) prior tothe start of the recording scan of the recording head.

Next, a threshold value (the value of record duty or recording density)recordable during the recording scan is obtained on the basis of thecapability (electric power supply amount) of the power supply of therecording apparatus. Comparison between this threshold value and therecord duty of the recording data is then effected.

If as the result of this comparison between the threshold value and therecord duty of the recording data, the threshold value is greater thanthe record duty of the recording data, ordinary scanning and recordingare effected. If, however, the record duty of the recording data isgreater than the threshold value, the number of nozzles (the number ofnozzles for discharging the ink therethrough) used in one cycle ofscanning is decreased and the recording operation is performed.

When for example, it is detected that the digital camera has beenconnected, the above-mentioned threshold value is changed to apredetermined threshold value. In order to supply electric power fromthe power supply of the recording apparatus to the digital camera, theconsumed electric power of the recording operation can be made smallerthan the consumed electric power of the recording operation whenelectric power supply is not effected to the digital camera.

A method of detecting the record duty will now be described withreference to FIGS. 3A to 3C. In the present embodiment, description willbe made of a case where color recording using yellow (Y, FIG. 3A),magenta (M, FIG. 3B) and cyan (C, FIG. 3C) of the inks the recordingapparatus has is effected. Also, it is to be understood that therecording head in the present embodiment has resolution of 600 DPI foreach color and has 256 nozzles.

An area corresponding to the nozzle width for Y×one scan is divided intoa plurality of blocks, and at that block unit, the record duty of therecording data is calculated (detected). The print data by which thedischarge of the ink is actually effected is ‘1’ in terms of binary dataand therefore, print data which is ‘1’ is counted. This data ‘1’ isso-called dot data.

In the present embodiment, as indicated at 301 to 303, the area isdivided into blocks of 256 dots in a sub-scanning direction×224 dots inthe main scanning direction, and the record duty is detected. The areaof these blocks need not be of this size, but can be a unit at which achange in the record duty can be detected as the load of the powersupply.

As regards the blocks to be counted, there may be adopted a method ofmaking the block size thereof still smaller, setting still a smallerblock area within the range of 256 dots in the sub-scanningdirection×224 dots in the main scanning direction, calculating therecord duty in that small area, adding the calculated value, anddetecting the record duty.

The main scanning direction is the scanning direction of the recordinghead. The sub-scanning direction is the conveying direction of therecording medium, and the arrangement direction of the nozzles of therecording head.

Also the recording data corresponding to the nozzles for magenta (M) andcyan (C), similarly to yellow (Y), are divided into blocks as indicatedby 304 to 306 and 307 to 309, respectively, and the record dutiesthereof are calculated (detected).

The calculation (detection) of these record duties is effected beforethe start of each scan for recording.

Reference is now had to FIGS. 4A to 4C to describe the comparisonbetween the record duty obtained by the detecting means for detectingthe record duty and the threshold value. This threshold value is set bythreshold value setting means.

In each block of 256 dots at the height×224 dots at the width, therecord duties (the count values of dot data) for Y, M and C are added.The result 402 of this addition and a duty 403 preset for each block arecompared with each other by a comparator 404 (FIG. 4B). The result 405of this comparison is outputted.

As shown in FIG. 4A, a block 401 has a block 401A, a block 401B, . . .arranged in the main scanning direction. Regarding the respectiveblocks, a comparing process is carried out in succession. The result ofthis is outputted for each block.

If as the result of this comparing process, the record duty (value)obtained by the detecting means is greater than the duty 403 preset foreach block, a flag is set to ‘1’. If the former is smaller than thelatter, the flag is set to ‘0’.

This flag, as shown in the table 405 of FIG. 4C, is providedcorrespondingly to each block. For example, 405A is the flag of a block401A, and 405B is the flag of a block 401B. If this flag is referred to,whether the record duty is greater than the duty 403 preset for eachblock can be judged with respect to the recording data of each block.

The duty 403 preset for each block is the record duty recordable duringthe above-described recording scan, and the threshold value.

This threshold value is a value (first value) predetermined on the basisof a supply capability of power source of the recording apparatus (powersupply specification), the consumed electric power of the mountedrecording head, the consumed electric power of the motors, etc., andalso an electric power value (or a numerical value corresponding to theelectric power value) consumable to drive during each recording scan.This threshold value is also a control parameter for suppressing theconsumed electric power.

This duty 403 preset for each block is carried out, for example, whenthe power ON of the recording apparatus or when the mounting of therecording head.

If in the recording of one scan, any one of the above-mentioned flags is‘1’ with respect to the above-described block, it represents that theconsumed amount (electric power load amount) for the recording operationis over the supply amount of the power supply of the recordingapparatus, and in this case, a supplied voltage to the recording headand a supplied voltage to the motor drop and as a result, an imagerecorded is deteriorated or a desired recording operation cannot beperformed.

Accordingly, if in the blocks corresponding to one scan, any one of theflags is set to ‘1’, the recording operation is changed in order tomitigate the load of the power supply. For example, the process ofthinning the data to be recorded, the process of increasing the thinningrate of the data to be recorded, the process of increasing the frequencyof the recording scans for a same area of the recording medium or thelike, is carried out.

The process of thinning the data to be recorded is, for example, theprocess of decreasing the amount of data used for one cycle of scanrecording by the use of a mask pattern. The process of increasing thethinning rate of the data to be recorded is, for example, the process ofusing a mask pattern of 20% thinning, instead of a mask pattern of 10%thinning. The process of increasing the frequency of the scans for asame area of the recording medium is, for example, the process ofcompleting an image by three cycles of scan recording, instead ofcompleting an image by one cycle of scan recording of a predeterminedarea.

FIG. 5 shows a flow chart of the present embodiment. The USB host of therecording apparatus conforms to the standard of USB, and detects that aUSB device (function) such as a digital camera has been connected(S501).

Further, the USB host of the recording apparatus demands configurationinformation from the connected function, and examines the facilities ofthe device. As one of them, it confirms whether the USB device which isthe function is a bus power device activated by being supplied withelectric power from Vbus (requiring the supply of electric power fromVbus) (502).

If the USB device which is the function is a bus power device, the duty403 preset for each block is changed to a different value (a secondvalue) (S503). That is, the control parameter for suppressing theconsumed electric power is changed.

This second value is a value smaller than the above-mentioned firstvalue. The consumed electric power of a recording operation performedwhen the record duty value (detected record duty value) is greater thanthis second value is smaller than the consumed electric power of arecording operation performed when the record duty value (detectedrecord duty value) is greater than the first value.

For example, when the record duty value is greater than the first value,the rate at which the data to be recorded is thinned is 25%, but whenthe record duty value is greater than the second value, the process ofincreasing the rate at which the data to be recorded is thinned to 40%is carried out. Also, as another example, when the record duty value isgreater than the first value, image recording is effected (an image iscompleted) on a same recording area of the recording medium by twocycles of main scan recording, but when the record duty value is greaterthan the second value, image recording is effected (an image iscompleted) by three cycles of main scan recording.

If the USB device which is the function is not a bus power device,advance is made to S504. At S504, comparison between the record duty 402detected for each block and the record duty 403 preset for each block iseffected.

If any one block (in which the detected record duty in a unit block≧therecord duty 403 preset for each block) exists (any one flag exists) inone scan, a recording operation with a controlled record duty isexecuted to thereby suppress the load to the power supply (S505).

If no block (in which the detected record duty in a unit block≧therecord duty 403 preset for each block) exists (no flag exists) in onescan, the recording mode is not changed but normal printing is executed(S506).

This control shown in FIG. 5 is effected, for example, at the start ofthe recording operation (for each page). Also, if non-connection (state)is detected at the timing of the recording operation (for each page),the process of changing the record duty preset for each block from thesecond value to the first value is carried out.

Thereby, in conformity with the connected or non-connected state of theUSB function such as a digital camera, the recording apparatus canperform the recording operation while keeping balance between theelectric power consumption and the recording speed.

When a device activated by being supplied with electric power isconnected, consumed electric power for the recording operation can bereduced and electric power supply can be effected to the deviceconnected to the recording apparatus.

The connection detecting process may be carried out for each main scanrecording operation. That is, even in a case where the USB function suchas a digital camera has been connected when recording data requiring agreat electric power load is being recorded, the consumed electric powercan be further reduced.

Second Embodiment

In a second embodiment, the schematic construction of the recordingapparatus and the power source supplying means are the same as those inthe first embodiment and therefore need not be described.

The operation of detecting the connection of the peripheral device (USBdevice) in the present embodiment will hereinafter be described withreference to the flow chart of FIG. 6. The processing of each step shownin FIG. 6 is executed, for example, by the interface control circuit ofFIG. 1.

First, in order to judge whether the peripheral device (USB device) isconnected, the voltage level of the data line is examined (step S601).If the voltage level of either one of the data lines is a thresholdvalue voltage or greater, at a step S602, it is judged that theperipheral device is connected, and when the connection is detected, thetransmission of configuration information is demanded of the peripheraldevice and the consumed current of the peripheral device is examined(step S603). On the other hand, if at the step S602, it is judged thatthe peripheral device is not connected, return is made to the step S601,where the voltage level of the data line is again examined.

From the consumed current of the peripheral device examined at the stepS603, whether the peripheral device is a bus power device is judged(step S604). If it is a bus power device, a supply flag representingthat the supply of electric power should be effected is set to ON, andthe value of the consumed current of the peripheral device is stored ina predetermined memory area (e.g. the RAM 109) (step S605), and thesupply of electric power is started. At the same time, setting for theconnected peripheral device is effected (step S606). On the other hand,if at the step S604, it is judged that the connected peripheral deviceis not a bus power device, the supply of electric power is not effected,but at the step S606, setting for the connected peripheral device iseffected.

FIG. 7 is a flow chart showing the operation during the execution of therecording operation in the present embodiment with respect to thesetting of a recording method. The processes of respective steps shownin FIG. 7 are executed, for example, by controlling each block in whichthe CPU_CORE 101 of FIG. 1 is concerned.

Whether a record command has been received from a host computer or aconnected peripheral device is judged (step S701), and if the recordcommand has been received, whether the supply flag for representing theelectric power supply to the peripheral device which is set at the stepS605 of FIG. 6 is ON is examined (step S702). On the other hand, if atthe step S701, the record command is not received, whether the recordcommand has been received is judged again at a predetermined interval.

If at the step S702, it is judged that the supply flag is ON, whethermulti-pass recording is set as the recording method is judged (stepS703). If the multi-pass recording is not set, the multi-pass recordingis set (step S704), the number of used nozzles in one pass and thenumber of passes are determined on the basis of the consumed currentvalue stored at the step S605 of FIG. 6 (step S705).

If at the step S703, the recording method is set to the multi-passrecording, the step S704 is not executed, but the step S705 is executed.

On the other hand, if at the step S702, it is judged that the supplyflag is not ON, that is, electric power supply to the peripheral deviceis not effected, a value about a recording method designated by therecord command (a control value for the recording operation) is set(step S706).

Recording is executed in accordance with the recording method (thenumber of used nozzles, the number of passes, etc.) set in the mannerdescribed above.

Third Embodiment

In a third embodiment, the schematic construction of the recordingapparatus and the power source supplying means are the same as those inthe first and second embodiments and therefore need not be described.

FIGS. 8A to 8C and FIGS. 9A to 9C are graphs briefly illustrating therelation of a variation with time (the axis of abscissas) in theconsumed current value (the axis of ordinates) about the recordingoperation. These FIGS. 8A to 8C and FIGS. 9A to 9C show that thecarriage motor is driven and the carriage scans, whereafter therecording paper is conveyed by the driving of the conveying motor (theamount of this conveyance corresponds to the number of nozzles used forrecording), and thereafter the carriage motor is again driven and thecarriage scans. This operation is repeated, whereby an image is formedon the recording paper. FIGS. 8A to 8C show the control in the presentembodiment, and FIGS. 9A to 9C show the control in the prior art.

FIGS. 8A and 9A show variations in the consumed current of the carriagemotor when the recording operation is performed. In these figures, theconsumed current reaches its peak after a predetermined time has elapsedafter the driving of the carriage motor has been started. FIGS. 8B and9B show variations in the consumed current of the conveying motor (LFmotor). FIGS. 8C and 9C show variations in the consumed current value ofthe two in total. In other words, they correspond to the sum of theconsumed electric power amounts of the two motors.

As can be seen from FIGS. 9A and 9B, the driving of the carriage motoris started before the driving of the conveying motor (LF motor) isterminated. Accordingly, in a period T, the carriage motor and theconveying motor are being driven at a time. The consumed current reachesits peak after a predetermined time has elapsed after the driving of thecarriage motor has been started. Accordingly, as shown in FIG. 9C, thepeak of the sum of the consumed current of the carriage motor and theconsumed current of the conveying motor becomes Imax.

On the other hand, as can be seen from FIGS. 8A and 8B, when the drivingof the carriage has been started, the conveying motor is stopped (is ina non-driven state). Accordingly, as shown in FIG. 8C, the peak of theconsumed electric power can be made lower than Imax shown in FIG. 9C.That is, the consumed electric power of the recording apparatus can besuppressed.

The consumed electric power of the recording apparatus includes, besidesthe consumed electric power shown in FIGS. 8C and 9C, the consumedelectric power for driving the recording head and the consumed electricpower to be supplied as the USB host.

When a digital camera or the like is connected to the recordingapparatus, the control of changing over the driving timing so as not todrive the carriage motor and the conveying motor at a time is effected,whereby the driving timing of the motors can be dispersed.

FIG. 10 shows a flow chart of the present embodiment. This control iseffect, for example, at a print job unit (one-page unit or plural-pageunit), and is effected before the start of the recording of that job.The recording apparatus operates as the USB host. The recordingapparatus conforms to the standard of USB, and detects that a USBfunction such as a digital camera has been connected (S1001). Further,the USB host of the recording apparatus demands configurationinformation from the connected function, and examines the facilities ofthe device. As one of them, whether the USB device which is the functionis a bus power device activated by being supplied with electric powerfrom Vbus is confirmed (S1002).

If the USB device which is the function is a bus power device, there isprovided an operating mode in which the carriage motor and the conveyingmotor are not driven at a time (S1003). Therefore, the driving starttiming of one (or both) of the carriage motor and the conveying motor ischanged. If the USB device which is the function is not a bus powerdevice, the printing (recording) mode is not changed, but a normalprinting mode is adopted (S1004). That is, when the recording operationis to be performed, the carriage motor and the conveying motor aredriven at a time. For example, at the timing whereat decelerationcontrol has been started in order that the carriage motor is stopped,the driving of the conveying motor which is in its stopped state isstarted. Or at the timing whereat deceleration control has been startedin order that the conveying motor is stopped, the driving of thecarriage motor which is in its stopped state may be started.

In the present embodiment, the connection to a digital camera is done bya USB interface. A signal line comprises the Vbus of power source, theD+ and D− of date lines, and GND (ground).

In the present embodiment, means for detecting the connection of thedigital camera conforms to the standard of the USB. Specifically, theUSB device has a pull-up resistor on one of the data lines, and can bedetected by the device being connected to a hub or the port of the host,and one of the data lines being pulled up to a threshold at a high sideor greater for 2.5 μs (microseconds) or longer.

Fourth Embodiment

While in the third embodiment, at the step S1003 of FIG. 10, the mode isthe operating mode in which the carriage motor and the conveying motorare not driven at a time (are prohibited from being driven at a time),use may be made of the control of shortening the time for which thecarriage motor and the conveying motor are driven at a time (forexample, shortening the period T of FIG. 9B to ¼). That is, during aperiod for which the consumed electric power of the carriage motor isrelatively low (e.g. during a predetermined period from after the startof driving), the driving timing is changed so as to drive the conveyingmotor.

For example, after the driving of the conveying motor has been started,the control of delaying the timing for starting the driving of thecarriage motor is effected (that is, the driving start time of thecarriage motor after the start of the driving of the conveying motor ismade great). This can be applied when for example, the accelerationdriving time of the carriage motor is long (when much time is requiredfor the consumed electric power of the carriage motor to increase).Thereby, the throughput can be prevented from being reduced more greatlythan when the concurrent driving of the carriage motor and the conveyingmotor is prohibited.

The other description is the same as the contents of the above-describedembodiments and therefore need not be made. While it is to be understoodthat the timing of this connection detection shown in FIG. 10 iseffected, for example, at a print job unit (one-page unit or plural-pageunit), this is not restrictive, but this timing may be effected at thestart of the recording operation. Also, when the interval of one mainscan recording operation is long, the connection detecting process maybe carried out at one main scan recording unit.

Thereby, in conformity with the connected or non-connected state of theUSB function such as a digital camera, the recording apparatus canperform the recording operation while keeping balance between theelectric power consumption and the recording speed.

As described above, in conformity with the connected/non-connected stateof an electric device such as a digital camera, the operation timing ofthe driving means of the recording apparatus can be changed to therebysuppress the peak of the power supply load, and yet suppress a reductionin the throughput. Thereby, electric power supply can also be effectedto the connected electronic device, and a reduction in the cost of thepower supply can also be realized.

Also, while the driving timing of the motors has been described withrespect to the relation between the conveying motor and the carriagemotor, these motors are not restrictive, but application may also bemade to the driving of other motors such as the feeding/discharge motorand the maintenance motor.

Fifth Embodiment

A fifth embodiment will hereinafter be described in detail withreference to the drawings. Also, as in the above-described embodiments,description will be made with an ink jet recording apparatus of a serialscan type as an example of the recording apparatus, and with a digitalcamera as an example of the connected device.

FIG. 11 is a block diagram schematically showing the construction of arecording apparatus according to the present embodiment.

The reference numeral 1101 designates a CPU, the reference numeral 1102denotes a ROM storing therein a control program to be executed by theCPU 1101 and other table data or the like, and the reference numeral1103 designates a RAM. This RAM 1103 is provided with a receptionbuffer, a print buffer, etc.

The functions of the reception buffer and the print buffer are the sameas those described in the first embodiment and therefore need not bedescribed.

The reference numeral 1105 denotes an ASIC which is a control portionfor controlling the operation of the recording apparatus together withthe CPU. The reference numeral 1104 designates an interface whicheffects the transmission and reception of data from a host computer 1120and a digital camera 1121.

The ASIC 1105 includes an interface (I/F) control circuit 1106 forcontrolling the interface (I/F) 1104, a data control circuit 1107 foreffecting the read/write control of data to the reception buffer and theprint buffer, a print data generating circuit 1108 for effecting thegeneration of print data, a recording head control circuit 1109 forforwarding the print data generated by the print data generating 1108,and effecting the discharge control of the ink of a recording head, anda motor control circuit (drive control circuit) 1110 for controlling thedriving of motors.

The motor control circuit 1110 controls the driving of a carriage motor(DC motor) 1112 for causing a carriage carrying a recording head 1111thereon to scan, a conveying motor (DC motor) 1113 for effecting theconveyance of a recording medium (e.g. recording paper), a feeding motor(stepping motor) 1114 for effecting the feeding of the recording medium,a maintenance motor (stepping motor) 1115 for effecting the cleaning,etc. of the recording head, and a discharge motor (DC motor) 1116 foeeffecting the discharge of the recording medium.

The printing operation of the recording apparatus according to thepresent embodiment will now be described. When the recording apparatusreceives image data or the like from the host computer 1120 through theinterface 1104, the image data or the like is stored in the receptionbuffer by the interface control circuit 1106 and the data controlcircuit 1107 of the ASIC 1105. The received data stored in the receptionbuffer is subjected to command analysis, and the image data is subjectedto print data processing by the print data generating circuit 1108. Theimage data subjected to this print data processing is then stored in theprint buffer.

When a predetermined amount of data is stored in the print buffer, theprint data is read out from the print buffer at predetermined timing bythe recording head control circuit 1109, and is forwarded to therecording head 1111.

A driving pulse is given to the recording head 1111 by the recordinghead control circuit 1109 while the recording head scans (moves)relative to the recording medium, whereby the ink is discharged from therecording head in conformity with the print data, and an image is formedon the recording medium.

As described above, the scanning by the recording head 1111, and thefeeding, conveyance and discharge of the recording medium are by thecarriage motor 1112, the feeding motor 1114, the conveying motor 1113and the discharge motor 1116 being driven by the motor control circuit1110.

Also in the data reception from the digital camera 1121, imageprocessing such as a binarizing process is effected by the print datagenerating circuit 1108, whereafter the generation of the print data iseffected and a recording operation is performed by a similar process.

FIG. 12 illustrates the interface control circuit 1106 and circuitsrelated thereto when as an example of an image pickup element, a digitalcamera is connected to the printer through a USB cable.

The digital camera 1121 is provided with a USB as an interface 1201, anda control circuit 1203 for controlling the operation of the digitalcamera.

Also, the interface 1104 in the printer 1200 is provided with ports notshown, such as a parallel port, an IEEE 1394 port, besides the USB. Theinterface control circuit 1106 includes a Vbus current detecting circuit1202 for detecting the current of Vbus, a Vbus control portion 1204,etc., and can switch on and off a source voltage Vbo for Vbus by aswitch. The reference numeral 1205 designates a power supply circuitwhich outputs a voltage Vp for driving the motors and the recording headby a power supply obtained from the outside, a voltage Vl for drivingthe CPU and the ASIC, a voltage Vbo for the control of Vbus, etc.

When here, the digital camera 1121 is connected to the printer 1200through the USB cable, transmission and reception by a predeterminedcommunication protocol along the standard of the USB are effected, andthe switch is closed by the Vbus control unit 1204 and the voltage Vbois given to the Vbus.

At this time, the digital camera 1121 demands a current of 100 mA orless, or demands a current of 100 mA or greater and 500 mA or less, andthis is detected by the Vbus current detecting circuit 1202 and theresult of the detection is transmitted to the Vbus control unit 1204.

If the current value supplied to the digital camera 1121 is 100 mA orless, a recording operation (for description, represented as e.g. anormal mode) is performed without the mode of the recording operationbeing changed over.

If the current value supplied to the digital camera 1121 is 100 mA orgreater and 500 mA or less, the Vbus control unit 1204 transmitsinformation to the CPU 1101 and at the same time, also transmitsinformation to the motor control circuit 1110. The motor control circuit1110 which has received this information changes over its operation modefrom the normal mode to a silent mode. This silent mode is a mode whichdoes not consume the current.

The silent mode will be described here. The performance required of therecording apparatus in recent years includes silencing. Due to thehigher speed of the recording operation, the working sounds during thefeeding of the medium, during the conveyance of the medium and duringthe discharge of the medium tend to become great and therefore,particularly in the printing in the nighttime or at a quiet place, suchsounds sometimes become offensive to the user's ear and the ambientenvironment.

So, the function of lowering the working sounds during the recordingoperation more than in the normal mode is the silent mode. Thechangeover to this silent mode is set for the recording apparatus byeffecting the setting of mode changeover from the host device using asoftware such as a printer driver by means of a user to thereby transmitthe result of this setting from the host to the recording apparatusthrough the interface. Also, by the setting of a printer driver, it isalso possible to set a time zone for making the silent mode effective.Thereby, in the nighttime, the recording apparatus can be operated inthe silent mode.

In the present embodiment, further, the changeover control between thesilent mode and the normal mode is effected in accordance with thecurrent value supplied to the digital camera 121.

Now, as regards the silent mode, when driving is effected by the use ofa stepping motor, in order to reduce the noise when the operations offeeding, conveying and discharging the recording medium are performed,or the noise when the cleaning operation and the protecting operation(capping operation) for the recording head are performed, the drivingcondition of the stepping motor is changed, for example, during thefeeding operation.

Specifically, with regard to the driving curve of the stepping motor,the pulse rate given to the motor within a predetermined time is greatlylowered to thereby reduce the driving current value. For example, thecontrol of reducing (suppressing) the driving current value to about 70%of the driving current value in the normal mode is effected.

That is, this can also be said to be a mode for suppressing the consumedcurrent during the operation. Similar control is also applied to duringthe conveyance and discharge of the recording medium to therebyaccomplish a reduction in the working sound of the recording operationand the suppression of the consumed electric power (current amount)during the recording operation.

FIG. 13 is a flow chart representing the processing carried out inaccordance with a current demanded by the device connected to therecording apparatus of the present invention. For example, let it beassumed that with the host computer and the printer connected togetherby a USB cable, the host computer and the printer are in their powersupply ON state.

When at S1301, a device such as a digital camera is connected to theprinter through the USB cable, transmission and reception by apredetermined communication protocol along the standard of the USB areeffected, and whether the device is a corresponding device is checkedup.

If at S1302, the device is not a corresponding device, the errorprocessing of S1308 such as the switching off of the Vbus power supplyand a notice to the user is executed.

If the device is a corresponding device, at S1303, a current required bythe device is detected. If at S1304, the result of the detection 100 mAor less, a recording operation is performed in the normal mode of S1306.If the result of the detection is greater then 100 mA, at S1305, whetherthe aforementioned current is 500 mA or less is judged.

If at S1305, the current is 500 mA or less, at S1307, changeover to thesilent mode is effected. If the current is greater than 500 mA, errorprocessing is executed at S1308.

Thus, when the connected device demands a current of power supply bus of100 mA or greater and 500 mA or less, the controlling method for therecording apparatus is changed over to the silent mode.

That is, the motor drive control is effected with the pulse rate reducedand the current value closed tight, whereby the consumed electric powercan be suppressed. The electric power corresponding to this suppressedamount can be allotted to the electric power supply to the connecteddevice. Thus, the current demanded by the device can be supplied stablywithout the power supply capacity of the recording apparatus beingincreased, and yet the recording operation as before can be performed.

The control flow has been described above, but when a current of 100 mAor greater is demanded, design may be made such that as before, theprocess of forcibly switching off Vbo by a switch can be selected by aprinter driver operated by a host computer.

Also, with regard to the driving condition of the stepping motor in theabove-described silent mode, the changed value thereof is not restrictedto 70%. Nor the stepping motor is restrictive, but the driving conditionof the DC motor may be changed. For example, the driving voltage valueor the duty value of the driving voltage for the DC motor can bechanged.

(Description of the Recording Apparatus Applied to the First Embodimentto the Fifth Embodiment)

While the first embodiment to the fifth embodiment have been describedabove, the recording apparatus applied to the above-describedembodiments will hereinafter be described. FIG. 14 is a perspective viewof the recording apparatus (printer). The reference numeral 1405designates a recording head, and is carried on a carriage 1404 and isreciprocally movable in the longitudinal direction thereof along a shaft1403. Ink discharged from the recording head arrives at a recordingmedium 1402 having its recording surface regulated by a platen 1401 witha minute interval from the recording head, and forms an image thereon.

A discharge signal is supplied to the recording head through a flexiblecable 1419 in accordance with image data. The reference numeral 1414 isa carriage motor for causing the carriage to scan along a shaft 1403.The reference numeral 1413 denotes a wire for transmitting the drivingforce of the motor 1414 to the carriage 1404. The reference numeral 1418designates a conveying motor coupled to the platen roller 1401 tothereby convey the recording medium 1402.

This recording head is of an ink jet type. A recording element iscomprised of a driving portion and a nozzle, and the driving portion cangive heat to the ink by a heater. The ink is film-boiled by this heat,and the ink is discharged from the nozzle by a pressure change caused bythe growth or contraction of a bubble by the film boiling.

Other Embodiments

Also, design may be made such that when with a host computer and theprinter connected together by a USB cable, the printer receives datafrom the host computer and starts its recording operation, the processitself of detecting whether a digital camera has been connected is notcarried out. That is, during a period from the start of the recordingoperation of the printer until the recording operation is completed, theprocess of prohibiting the detection of the connection of the printer tothe digital camera may be carried out. Or during the period from thestart of the recording operation of the printer until the recordingoperation is completed, the detection of the connection of the printerto the digital camera may be effected, but as regards electric powersupply, the control of completing the recording operation may beeffected.

While description has been made with a digital camera taken as anexample of the USB function conforming to the standard of USB, thedigital camera is not restrictive, but application may also be made toan electronic device (a memory device or a communication device) whichsatisfies (conforms to) this USB standard. Application may also be madeto a case where an electric fan or a light emitting device (light) orthe like is connected.

The form of the printer is not restricted to a printer of a serial type,but may be a printer using a recording head of a full line type having alength corresponding to the maximum recording width of a recordingmedium on which the printer can record.

1. A recording apparatus provided with an interface capable of supplyingan electric power to an electronic apparatus connected thereto, and ofperforming a recording operation on a recording medium by the use of arecording head, comprising: a power source supplying unit for supplyingpredetermined electric power to the electronic apparatus connected tothe interface; a detecting unit for detecting that the electronicapparatus has been connected; an acquiring unit for acquiringinformation indicating that the electronic apparatus is activated bybeing supplied with the predetermined electric power through theinterface; and a control unit for changing over the control of therecording operation, based on detection of the connection by thedetecting unit and the information acquired by the acquiring unit.
 2. Arecording apparatus according to claim 1, wherein the interface conformsto a USB standard.
 3. A recording apparatus provided with an interfacecapable of supplying an electric power to an electronic apparatusconnected thereto, and of performing a recording operation on arecording medium by the use of a recording head, comprising: a powersource supplying unit for supplying predetermined electric power to theelectronic apparatus connected to the interface; a detecting unit fordetecting that the electronic apparatus has been connected; an acquiringunit for acquiring information corresponding to power that theelectronic apparatus requires; and a control unit for changing over thecontrol of the recording operation, based on detection of the connectionby the detecting unit and the information acquired by the acquiringunit.
 4. A recording apparatus according to claim 3, wherein theinterface conforms to the USB standard.